A laminate obtained by laminating a material different from the base material on the base material is used for various applications depending on the combination of materials. For example, the laminate obtained by laminating ceramic or cermet on an aluminum base material by thermal spraying is used for a substrate supporting device or a stage heater which adjusts the temperature of the semiconductor substrate in a semiconductor manufacturing process.
Meanwhile, when a thermal expansion coefficient of the base material is different from a thermal expansion coefficient of the spray coating film formed on the base material, if the base material is heated during use of the laminate, crack may occur in the spray coating film due to stress. In order to suppress an occurrence of such a crack or increase the temperature at which the crack begins to occur, a technique of alleviating the stress by providing a material having a thermal expansion coefficient between the base material and the spray coating film or a porous material having low rigidity as an intermediate layer has been known. Further, Patent Literature 1 discloses a technique of suppressing an occurrence of tensile stress in the spray coating film when heating the base material, by performing the thermal spraying on a plate portion serving as the base material at a work temperature which generates the residual stress at which the crack does not occur in actual use temperature of the substrate supporting device.